Scientists develop new test enabling early diagnosis of liver cancer

Washington: Scientists, including Indian-origin researchers, have developed a new test that can distinguish early liver cancer cells from nearly identical normal liver cells by giving them a distinctive red-brown hue.

The inability to definitively tell the difference between them often means the disease is detected late when treatment options are less effective, said Dr Ravindra Kolhe, pathologist and Medical Director of the Georgia Esoteric, Molecular Labs at the Medical College of Georgia at Georgia Regents University. "There is no definitive test for early diagnosis of liver cancer. Our test adds a level of comfort for making the diagnosis," said Kolhe, lead author of the study.

Early liver cancer is mostly silent. By the time it's large enough to cause classic symptoms such as abdominal pain and weight loss, the cancer cells look distinctive but the liver is failing. The myriad of treatment options, from removing the diseased portion of the liver to liver transplants to freezing or heating cancer cells, have a high chance of failing as well, Kolhe said.

Kolhe began collaborating with BioGenex laboratories, a California company with expertise in cell and tissue testing, to develop a probe that gives cancer cells the distinctive red-brown hue. The probe detects and stains a microRNA called mir-21, which is found in liver cancer but not healthy liver cells, Kolhe said.

Unlike RNA, microRNA doesn't make proteins rather helps control proteins that are expressed by RNA. That means it's more stable and can survive harsh chemicals normally used to prepare the biopsy for microscopic evaluation. For the study, they used their probe on biopsies of 10 healthy livers and 10 livers with early cancers. In every case of liver cancer, the biopsy took on the red-brown hue. The probe was not detected in normal cells.

The studies were done retrospectively, so they already knew which patients ultimately were diagnosed with cancer. They are now using the test on 200 similar cases of liver cancer. The group also is exploring this approach in other hard-to-detect-early cancers. Kolhe worked with pathology resident Dr Puneeta Vasa to identify microRNAs selectively expressed in melanoma.

Under the microscope, the potentially deadly skin cancer cells look a lot like common mole cells. The findings will be presented at the American Society of Clinical Pathology 2013 Annual Meeting in Chicago.